Blow-off valve.



P. A. WARDLAW. BLOW oFF VALVE.

APPLIOATION FILED DBO. 21, 1909.

Patented May 30, 1911.

All.

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UNTTED sTATEs PATENT onirica.

FRANK A. WARDLAW, 0F BROOKLYN, NEW YORK.

:BLOW-OFF VALVE.

Specification of Letters Patent.

Application led December 21, 1909.

Patented May 30, 1911. Serial No. 534,289.

To all whom it may concern:

Be it known that I, FRANK A. WARDLAW, a citizen of the United States,and a resident of Brooklyn, in the county of Kings and State of NewYork, have invented certain newv and useful Improvements in Blow-OffValves, of which the following is a full, clear, and exactspecification.

My invention relates to improvements in blow-off valves,'and is designedto overcome the constant troubles and continuous expense necessary forthe maintenance of what blow-off valve is forced against its seat bylocomotive drivers and remen.

The first defect above mentioned is overcome in my valve by theinterposition of a shut-off cock between the blow-0H valve proper andthe boiler, that forms part of the same 'casting as that containing theblow-oit` valve. The last mentioned, z'. e. the avoidance of damage dueto a careless or rough handling, is overeome by completely reversing thedirection of flow through the valve, whereby it is closed by thepressure from the boiler itself, and is so constructed as to precludeanypossibility of its being forced to its seat by exteriormeans.

'In 'the accompanying drawings wherein similar letters of reference areused to indicate corresponding parts in each of the sevcates the bodyofthe valve that may be pro-- blow-off valve G, connected loosely to itby means of the lock-nut H. A space exists between the bottom of thelock-nut I-I and the head of the blow-off valve spindle I, whichslightly exceeds the thickness of the semiplastic seatingJ of the valve,that permits of the metallic portion of the valve K descending andforming the seal in the event of the destruction of the semiplasticportion J. A cup-shaped metallic circular disk L that slides freely onvalve spindle I is provided, to cover theedges of the semiplasticseating J when raised, so as to prevent its being worn away by theaction of the out-rushing water. An annular ring is made in the top ofthe valve chamber casting as shown at M, in which is laid, so as to forma snug fit, the packing ring N, which may be of woodite, klingerit, orany other suitable packing, its object being to prevent any leakage whenthe plug F is screwed to the closed position; it also serves to form asteam andwatertight joint between the body A of the blow-off valve, andthe cap O that carries the stuffingbox P, when the plug is screwed tothe open position. Cap O and body A are fastened together as shown bybolts and nuts extending through their flanges, or by means ofstud-bolts let into the casting A, the cap 0 being placed over thesestud-bolts and tightened down by nuts. Cap O serves three purposes viz:it maintains a tight joint at X when plug F is in the open position; itcarries the stuiing-box P that prevents any leakage around the operatingspindle S, and it serves as a stopV for the plug F, limiting thedistance to which it can be raised. As will be Seen by the drawings,there is a clear space between the top of the recess in the plug F, andthe head of thevalve spindle I,

when plug F is screwed to closed position, thus making it Vimpossiblefor the operative to force the valve against its seat by means.

of long spanners, or other devices, its proper closing being entirelyautomatic and beyond his control. The operating spindle may be providedwith a hand-wheel, or simply a square head, to be operated by means of aproper spanner from the ground or the engine as desired.

The blow-off valve proper G, is composed of metallic and non-metallicsubstances, the latter being of a semiplastic nature capable ofresisting the high pressures and temperatures of the vapors, gases orliquids passing through the valve without altering its shape, oraltering it to so slight a degree as to be negligible, such as woodite,ebonite, vulcanized rubber, lenolite, etc. This semiplastic material isfirmly gripped between the two metallic parts of the valve Gr and T byscrewing them together as shown, the under surface of G and the uppersurface of T having grooves, annular rings, or teeth cut in them, toprevent the dislocation of the semiplastic material. It is still furthersecured to its place by re-heating after being assembled and tightenedcold, and again tightened by screwing the metallic parts together atrifle more. This same re-heating and re-tightening also tends toprevent any further eXpansion or enlargement of the lsemiplasticmaterial when subjected to the high pressures and temperatures of thevapors, gases or liquids for which it is to be used.

The operation of the invention will be readily understood from theforegoing description.

The valve is connected to the boiler by flanged or screwed connectionsaccording to previous practice. The flow from the boiler to theatmosphere is in the direction indicated by the arrows.V The valve isshown as completely closed, both by means of the valve G and theplug-cock B. In normal working the plug-cock B remains continually open,or moved to a quarter turn from the position shown. This throws the fullboiler pressure on to the upper surface of the valve G, forcing ittightly against its seat and preventing the escape of the water. When itis desired to blow down the boiler, a suitable spanner is applied to thesquare head of the spindle S, or the hand-wheel turned as the case maybe, and the plug F unscrewed until its flanged head meets the undersurface of the cap O. This raises the valve proper Gr tothe requireddistance, allowing the water to discharge. When it is desired to closethe valve, the spindle S is turned in the contrary direction, loweringthe plug F and valve Gr until the flanged head of F is firmly compressedagainst the packing ring N. Long before the flanged head of F has beenseated on the packing, however, it will have lost any control over thevalve G which will have been already seated by the boiler pressure, notwith a blow or any forcing, but gradually and easily until the seal iscomplete. The engine-drivers or firemen can not force it as they do thevalves at present in service. Should any accident occur to valve orvalve seat, or to packings N or R, these can be at once repaired byturning the plug-cock B one-quarter turn, thus shutting ofiI allpressure from the boiler, a feature not existing in any other blow-odvalve at present in use. The valve Gr is guided both top and bottominsuring perfect seating.

The operation of the form shown in Fig..

2 is substantially like that shown in Fig. l, there being a slightdifference in the construction of certain details which might simplifythe manufacture of the device. In this modification the spindle I andhead z" are made in one piece, and slip into the valve proper, insteadof being fastened to it as in Fig. l by lock-nut I-I.

I-Iaving thus fully described my invention what I claim as new anddesire to secure by Letters Patent of the United States is 1. In ablow-oft' valve device, the combination with a turning plug, of a valveloosely connected thereto, said valve consisting of a metallic memberand a semi-plastic member, and a cup-shaped cover for said valve looselymounted on said valve.

2. A blow-0E valve device comprising a casing provided with a threadedplug seat, a plug fitting said seat, and formed at its inner end with arecess, a valve spindle eX- tending into said recess, a nut forsecuring` and guiding said spindle, a valve on said spindle consistingpartly of metal and partly of semiplastic material, and a cup shapedprotector for said valve inclosing the latter and loosely mounted onsaid spindle.

3. In a blow-off valve device, the combination with a turning plug of avalve spindle loosely connected thereto, a valve secured to said spindleand consisting of a metallic member, and a semiplastic member, and acup-shaped cover for said valve loosely mounted on said spindle.

4C. A blow-0H' valve device, comprising a casing provided with athreaded plug seat, a plug fitting said seat, a valve spindle looselyconnected to said plug, a composite valve carried by said spindle, meansfor turning said plug and a cup-shaped cover for said valve` said coverbeing loosely mounted on said spindle.

5. A blow-off' device comprising a casingl said spindle, a valve on saidspindle consistname to this specification in the presence of ing partlyof metal and partly of semiplastic two subscribing witnesses. material,a cup sha ed protector for said valve inclosing the utter, and a shut ofFRANK A' WARDLAVV' cock or valve inter osed between the blow- Witnesses:olf valve and the boller end of the casing. LOUIS E. YOUNG,

In testimony whereof I have signed my CHARLES M. CHANDLER;

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of latents, Washington, I). C.

